<div>Hello</div>
<style>
    div {
        border: 1px solid blue;
        height: 300px;
        /*background-color: skyblue;*/
        /*background-image: url("./images/facebook.png");*/
        background-repeat: no-repeat;
        /*background-repeat: repeat-x;*/
        /*background-repeat: repeat-y;*/
        /*background-position: 100px;*/
        /*background-position: 10%;*/
        /*background-position: 100px 200px;*/
        /*background: url("./images/facebook.png") no-repeat 100px 200px;*/
        background-image: url("./images/mac.jpg");
        background-size: 100% 100%;
        /*background-size: auto 100%;*/
        /*background-size: 50% auto;*/
    }

</style>